People often focus on traits and characteristics that children inherit from their parents, but forget that a person's genetic makeup can go back much further than just one generation. As scientific methods and testing expand, so too does our understanding of a person's genetic history. Who are we and how much of our personal make up is attributed to parents? What if there were other people who set the stage for certain of traits, well before a person's parents were born? Well, these people are our grandparents, and science is proving that they are more significant to our understanding of genetics than we previously thought.
Curiosity about ancestral roots has peaked in the last decade or so, with many people opting to do research to find out more about their family history. Popular websites like Ancestry.com have seen an influx of members, all seeking answers about their background. The good news? Scientific advancements of the 21st Century can now give us more precise answers to the questions we have about our roots. If a person has ever been curious about how they got their beautiful eye colour, or why they have a predisposition to certain illnesses, read on. Here are Traits Babies Only Get From Grandparents: 15 Features That Skip A Generation
15 Chromosome Structure
A chromosome in essentially a molecule that contains your DNA and genetic materials. In healthy humans, 22 pairs of autosome chromosomes are present, as well as one pair of allosome chromosomes (X or Y, used to determine the baby's gender). So what does this all mean in non-scientific garble? The autosome chromosomes are where all of your genetic hereditary details are stored. Certain parts of your DNA are passed down from your paternal side, and some from your maternal side.
In theory, this should be about a 50/50 split. But, because there are more genes in the X chromosome (the female dominant chromosome) than the Y chromosome (the male dominant chromosome), a child will naturally inherit a little bit more than half of their DNA from their maternal side.
Going back further, this would mean that your mother would've inherited about the same amount from her parents, and so on and on and on. The DNA continues to trickle down into every subsequent generation, even if the percentages are slightly lesser each time. So even if your dominant DNA is directly inherited from your parents, it has a history that goes back much farther!
14 Eye Colour
Have you ever seen a child with a beautiful eye colour, that neither of their parents share with them? This is more common that one would think, and the logic is quite simple. As your DNA is made up of approximately half of your mothers genes, and half of your fathers, you would naturally assume that you would share eye colour with one of your parents. But don't forget, their DNA was also inherited the same way, and so was their parents'.
If your parents have brown eyes, but your grandmother had blue eyes, it's completely possible that you would inherit her blue eye colour. What we're dealing with here is something called a recessive gene, which means that the gene for blue eyes exists somewhere in your historical DNA makeup.
It might not come directly from your parents, so your odds of having blue eyes is inherently lower, but it is still quite possible. Another recessive gene that can cause a trait to skip a generation is hair colour or texture. So if your parents both have straight hair, and yours is ridiculously curly, call off the "am I adopted?" thoughts and chalk it up to biology instead!
13 Predisposition To Have Twins
We've all heard that predisposition to having twins usually skips a generation, but what are the real odds of having twins whether or not you have them in the family?
The twin gene usually refers to fraternal twins, as that phenomenon is caused by the X chromosome. The occurrence of identical twins, however, is more of an anomaly, and often is the result of pure chance.
Because identical twins result from one fertilized egg splitting in two, and both babies sharing one placenta, it is impossible to attribute to a predetermined set of traits. If your family has more than one set of identical twins, they don't actually have a genetic link! Fraternal twins can occur in any generation within the same family, and only appear to skip a generation because the chromosome is only carried by the woman. So for example, if your grandmother was a twin, but she was your father's mother, your father couldn't have carried the gene and had twins himself (unless your mother had the twin gene from her side of the family, or it was by chance). If you, a woman, have twins, it can be a result of the passed down DNA inherited from your paternal grandmother. Wow. That hurts the brain.
12 Recessive Traits
Recessive traits are those that appear where there is an absence of a dominant trait. Because recessive traits have less power than dominant traits, organisms need two recessive genes before a recessive trait is presented.
So, you essentially need to have the gene from both your mother and father's side before it can appear in your DNA.
An example of a recessive trait would be something like heart disease. If both your paternal and maternal grandmother's had heart disease, but both of your parents are clear of heart disease, you can still have health problems. This is because both of your parents are carriers of the genes that result in the disease, and they can still pass it on to you recessively. This is why doctors often ask you for your medical history, and ask you on what side of the family certain diseases occurred. Although they cannot predict anything with your health history alone, it can help you to become more proactive in diagnosing potential illnesses and diseases in the future. If you know what to be wary of, you can equip yourself for better health. If you are unaware of your family history, it could be helpful to ask a member of your family that might be able to help you out.
11 Certain Diseases
Not all diseases are hereditary, which means that if your parents or grandparents suffered from some sort of medical affliction, it doesn't necessarily put you at a higher risk of having the same fate.
If a parent, for example, has a dominant gene disease, the children born to this parent have a 50% chance of inheriting the disease (does not mean that the disease will ever surface or pose a problem for the child, as the disease can remain dormant).
A recessive genetic disease has a lowered risk of inheritance, which goes down to 25%, roughly. Chromosomal abnormalities which result in certain conditions for the child can occur in any pregnancy. For the most part, conditions such as Down's Syndrome occur when there are chromosomal shortages or excesses. Occurrences of multiple miscarriages or fertility issues can be linked to genetic recessive traits, so these are all things that should be investigated prior to trying to conceive. If you have any way of finding out what kind of pregnancy issues the women in your family had (if any) it could help your doctor screen you for different possibilities. Of course not everything can be chalked up to genetics, so we have to expect that sometimes nature simply throws us curveballs when it comes to our health.
10 Predisposition To Certain Struggles
Having a hard time maintaining a healthy weight? For certain people, even exercise and a healthy diet are not enough to stave away the predisposition they have to obesity.
This genetic trait can be passed down from recessive or dominant genes, although it is quite rare. Many people might have the predisposition to sizes based on genetics, but lifestyle and foood are bigger factors in the long run.
Serious cases of obesity running in the family can be attributed to genetic mutations. For example, a condition called monogenetic obesity is caused by spontaneous mutations of the genes that regulate appetite control and the intake of food. These mutations do not occur frequently, but they can be passed down. The best way to target this condition, doctors agree, is to develop healthy lifestyle habits that can be effective in weight control. Regular exercise, a balanced and moderate diet and lots of water are the best tools to keep your weight at a healthy level. Getting enough rest is another key factor is the maintenance of a healthy weight. Studies show that getting less than 6 hours of sleep per night can be counterproductive when it comes to losing or maintaining weight.
Longevity is a trait that can be either a good or bad inheritance, depending on your family history! Unlike obesity, the longevity trait definitely has an effect on your expected life span, and here's why.
Scientists have proven that the more damaged genes a person has, the less long his lifespan. Similarly, the more healthy genes that a person has, the longer their life expectancy.
This is pretty basic science and biology, but there is also no exact formula that can give us a range of how long we will live. Genetics only account for roughly 20%-30% of our chances of surviving to the age of 85 or beyond. The rest is really up to us! Our own habits and exposures greatly influences our quality of life. Similarly, scientists are relying more and more on the effects of stress on the body to explain disease, premature aging and illness. Harvard researchers have equated physiological stress, which can often be the result of negative feelings or emotions, with lower life expectancy. Never before has it been so important for us to take care of our emotional well-being, which can be seen with the rise of self-help literature, seminars and events.
8 Emotional Problems
Now that research has proven that our cells can retain traumatic moments, and particularly emotionally traumatic moments, we can start to understand ourselves in respect to our ancestors.
Just as damaged cells can be passed on from generation to generation, so too can cells that have been through emotional or psychological stress. There have been so many different reports of the children and grand-children of war veterans feeling their intense sadness, for example, at different moments in their lives.
Some people even swear that they have experienced intense moments that their parents or grandparents went through, although these reporting's are often discredited as paranormal nonsense. Now, science is catching up in a way that we can actually give explanations as to how these things can happen, without going into ghost stories! Our DNA is so much more complex than we give it credit for, and because we are only making these discoveries now, the information is all quite new and somewhat hard to believe! The next time you feel weepy and down, perhaps you are tapping into some old hurts that your grandmother experienced when she was younger! It's kind of like time travel, in a way, which is really cool.
7 Genetic Defects
Genetic defects occur when there is one, or several abnormalities in the genome. Generally speaking, the occurrence of genetic disorders are quite rare, and the odds of being afflicted are usually one in every several thousand, or in some cases, one in millions.
Genetic disorders can be hereditary, or due to mutated genes at the embryonic level.
Within the spectrum of genetic disorders are single-gene and multiple-gene defects. Single-gene defects affect one mutated gene, and account for roughly 4000 human diseases. These can be passed down from recessive or dominant genes. Sickle-cell anemia is one example of a single-gene defect. Multiple-gene defects are the result of two or more genes being mutated, and are more likely due to environmental factors than hereditary ones. Although, these defects can be passed down, they are more complex and it's much harder to pinpoint the exact origin. Heart disease, asthma, multiple sclerosis and diabetes are part of the web of multiple-gene defects. Genetic disorders and diseases are generally diagnosed at birth, or at the latest, in early childhood. Some genetic disorders, such as Down's Syndrome, can be detected prior to birth, with certain tests being carried out during pregnancy to determine the risk factor.
Ever wonder why someone might have a face full of freckles, but no one else in their immediate family seems to have any?
This is another case of a recessive trait that can skip a generation, or two. Generally, freckles appear in people with very fair complexions and light hair.
These people tend to have a lower level of melanin, which is a skin pigment which helps to protect against UV light, which is naturally occurring in sunlight. Some people are born without freckles and develop them over time due to their inherited levels of melanin. Most people have freckles on their faces, as this is the area of the body that is most exposed to sunlight during the day. Although, there are cases of people who literally have freckles on every inch of their bodies. Laser treatments can help to reduce the appearance of freckles, but this is only for cosmetic reasons. There are no risks to having a body full of freckles. Freckles are sometimes confused with liver spots, which are formed after years of exposure to the sun. These are usually found in older people, and are sometimes referred to as "age spots".
5 Red Hair
Red or ginger coloured hair is the rarest naturally occurring hair shade, with approximately 1-2% of the human population sporting fiery toned locks.
Most commonly, red hair occurs in people who have two copies of the recessive allele, and the majority of people with red hair are of Western European or Northern European descent.
This explains why a majority of Irish people have red hair, even if they do not live in Ireland. The genes simply pass down from past generations who possibly came from these countries. It is estimated that the gene responsible for the occurrence of red hair in humans dates back anywhere from 20,000 to 100,000 years. That's not to say that there weren't redheads before that, but the current active gene is at least that old. As with anything rare, redheads have often been the target of bullying or, admiration. Redheads have often been accused of having fiery temperaments, but this is clearly just an old wives tale. There has been no link proven between personality traits and hair colour, but who knows what science might find in the next decade or so? And if your hair color doesn't match your personality, you can always dye it until it does!
4 Cleft Chin
A cleft chin is essentially a dimple that occurs in the middle of the chin, where the jaw bone meets under the mouth. Generally, it is the result of an incorrectly fused left and right side of the jaw bone.
Although having a cleft chin is not representative of having any underlying health issues, it is very often passed down from dominant genes, meaning that if one of your parents has a cleft chin, you have a high chance of having one as well.
Furthermore, you can get this condition passed down from recessive genes, although the occurrence of this is rare. European and Middle Eastern populations have the highest prevalence of cleft chins in the world, and in some cultures it is seen as a sign of beauty and prestige. In fact, some people even opt to have cosmetic surgery to insert an artificial cleft chin. For those who aren't fans of their clefts, they can even add fillers to remove the appearance of the dimple. In Persian folklore, the cleft chin is referred to as the "chin pit". As the tale goes, the pit is where the lover gets trapped, and once you fall into a chin pit, you never come back! So do be very careful around people with cleft chins!
3 Colour Blindness
Colour blindness is almost always attributed to genetics. Colour blindness can indicate an inability to see colours, a decreased scope of colours, or difficulty in differentiating colours. The biggest challenges with colour blindness can be shopping for clothes and fruits, and seeing the colour of the traffic lights. Most of the issues associated are minor, and people generally adapt to their outside environment quite quickly. Once the problem is diagnosed, it's even easier to make the necessary changes to lifestyle to make sure that it doesn't get in the way!
Because the genes responsible for colour blindness are mostly associated with the X chromosome, males are more likely to be affected by this condition. Because women carry two X chromosomes, the damaged one is usually compensated by the non-damaged one, and the result is a more balanced gene.
Males, however, only have one X chromosome, and thus have nothing to naturally counter the effects of the damage. Non genetic reasons for colour blindness can include physical or chemical damage to the eye, brain or optic nerve. Generally, colour blindness can easily be detected with a very simple test carried out by either an optometrist or a family doctor.
Our personal fears are so unique to each of us, but they might actually stem from cell memories from long ago. We know that damaged cells can be passed on via DNA, and so can traumatized cells. So what's different with a fear? Something that makes us afraid or fearful puts us into fight or flight mode. When in this primal mode, we are basically set up for survival. The mechanism is available to us for dangerous or life threatening situations, but can also be activated when we are afraid, even if we are not in any danger. But, due to the nature of fight or flight, the physiology of our cells changes if the body is too often in fight or flight. Since all non-critical systems shut down, our cells can be affected, and this damage can be passed on from one generation to another. Similarly, you might share a phobia or fear with a parent of grandparent, simply because you have access to the emotional impact that the fear had on your ancestors genes. This is why anxiety and panic disorders are often passed on from dominant or recessive genes. If your mother or grandfather had an anxiety disorder, you might be more susceptible to suffering from one yourself.
1 A Few Too Many
Sadly, not everything that we inherit from our ancestors is glitter and gold! It would be nice if the only inheritance we received was a big check and a predisposition to a long life! Addiction to drinks is definitely something that can be passed down through dominant or recessive genes, although, it's a tough topic to broach, since the spectrum of alcohol use disorder (AUD) is quick far-reaching. Since experts can't even agree on what exactly constitutes the condition, the diagnosis is harder to come by. Of course, we can pinpoint when our drinking is getting out of hand. In general, if you feel like drinking alcohol is affecting some part of your life in a negative way, it's time to consider putting the bottle down. Sometimes, alcohol problems in family members isn't obvious, which causes even more confusion for second generation problematic drinkers. We don't always know exactly how much our grandparents drank, or the reasons for their drinking. These days, it's becoming more and more normalized to not drink any alcohol, so this is also a great preventative option if you are worried about having future problems with alcohol. You can always talk to your doctor about this as well, if you want to have additional resources and support.